Control valve for vessel gas water heater

Abstract

A control valve for a vessel gas water heater includes a single governor for controlling a wider range of the flow of gas from pilot supply to main supply. Once an ignition knob 1 is pressed and turned to open the magnetic valve V 1 and ignite the pilot burner PB, the magnetic valve V 1 is maintained open by the electromotive force of a thermocouple TC heated by a pilot flame c. When the ignition knob 1 is released from being pressed, and turned further to open the plunger valve V 3 , the boiler is shifted to the standby state for enabling the supply of gas to the main burner MB. Meanwhile, a sensor rod B is mounted in a reservoir A for contracting and expanding depending on the temperature of the hot water in the reservoir A to open and close the snap valve V 5 , thus controlling the combustion and its cancellation in the main burner MB. Accordingly, the temperature of the hot water in the reservoir A can automatically be controlled in the vessel gas water heater. In particular, a single governor is provided in which the seat tightness between its valve V 4 and valve seat is improved with the use of at least a rubber molding 17 a and the gas valve V 4 is prevented from tilting by a guide pin 20 freely fitted in a shaft 18 of the valve, thus controlling the flow of gas to the main burner MB and to the pilot burner PB for a wider range from main supply to pilot supply.

What is claimed is:  
     
       1. A control valve for a vessel gas water heater having an ignition knob pressed and turned for opening a magnetic valve and igniting a pilot burner, the magnetic valve maintained open by an electromotive force of a thermocouple heated with a pilot flame, and then, the ignition knob released from being pressed, and turned further for opening a plunger valve to enable the supply of gas to a main burner, and having a sensor rod for contracting and expanding depending on the temperature of hot water in a reservoir to open and close a snap valve and thus proceed and cancel the combustion in the main burner for automatically controlling the temperature of the hot water in the reservoir to a desired level, characterized by: 
       a single governor valve unit arranged in that the positional relationship between a valve and a valve seat of said single governor valve unit is correctly maintained to have a wide range of the flow of gas from a pilot supply to a main supply, thus enabling stable control over both the flow of gas to the main burner and the flow of gas to the pilot burner.  
     
     
       2. A control valve for a vessel gas water heater according to  claim 1 , wherein the governor valve is also arranged in that the interfacial accuracy between the valve and the valve seat is improved and the valve is prevented from tilting. 
     
     
       3. A control valve for a vessel gas water heater according to  claim 1 , wherein the valve seat for the valve is increased in the seating tightness using a rubber molding and fine polishing. 
     
     
       4. A control valve for a vessel gas water heater according to  claim 1 , wherein the valve is prevented from tilting by a guide pin freely fitted in a shaft of the valve. 
     
     
       5. A control valve for a vessel gas water heater according to  claim 1 , wherein the pilot burner is a constantly flaming type pilot burner designed for also heating a thermocouple. 
     
     
       6. A control valve for a vessel gas water heater according to  claim 2 , wherein the valve seat for the valve is increased in the seating tightness using a rubber molding and fine polishing. 
     
     
       7. A control valve for a vessel gas water heater according to  claim 2 , wherein the valve is prevented from tilting by a guide pin freely fitted in a shaft of the valve.